The present invention pertains generally to helmet lighting systems. More particularly, the present invention pertains to a motorcycle helmet lighting system. The present invention is particularly, but not exclusively, useful for a motorcycle helmet lighting system capable of establishing wireless links between a transmitter mounted on a motorcycle and one or more motorcycle helmets.
In the mid 80""s, the U.S. government researched automotive tail light positioning and found that significantly fewer accidents occur in vehicles having a brake light positioned at or near the highest point on the rear of the vehicle. In 1986, the U.S. government mandated that automobiles sold in the U.S. be equipped with a third brake light positioned near the highest point on the rear of the vehicle. To date, a similar law has not been passed for motorcycles.
The risks associated with riding a motorcycle are generally higher than driving an automobile for several reasons. First, motorcycles are smaller than automobiles and other motorists often have a hard time seeing motorcycles on the roads. Further, motorcycles are generally capable of higher rates of acceleration than automobiles causing other motorists to often lose track of the position of a nearby motorcycle. Also, motorcycles are generally capable of higher rates of de-acceleration than automobiles causing motorcycles to often be hit from behind by motorists that are unable to stop in time. Finally, motorcycles lack the weight, protective structure and other assorted safety devices such as airbags that are offered by automobiles.
A typical tail light assembly for a motorcycle includes a running light, a brake light, turn indicators and hazard indicators. For most motorcycles, the running light is always lit when the ignition circuit is energized. In a few motorcycles, the running light is only energized when the headlight is manually turned on by the rider. Typically the tail light is mounted at the rear of the motorcycle above the rear fender. Depending on the size and style of the motorcycle, the tail light is often relatively low to the ground and hard to see by other motorists.
Some states now require motorcyclist to wear helmets. To be effective as a safety device, a motorcycle helmet must be properly sized to fit the wearer. Typically, a motorcycle owner acquires a properly sized helmet for personal use and an additional helmet for passenger use. The passenger helmet may or may not be sized for a specific individual. When a helmet lighting system is used, it is important that the light on the drivers helmet be operative when a passenger is not riding on the motorcycle. Additionally, when a passenger is riding on the motorcycle, it is important that the light on the passengers helmet be operative and the light on the drivers helmet be inoperative. This setup avoids shining a bright light in the passenger""s face.
Several additional safety concerns must be considered when contemplating the installation of a lighting system on a helmet. First, a wireless link between the helmet and the motorcycle is preferred over a wired system to prevent a variety of possible wire related injuries that could occur during an accident. Second, safe voltages and lamp temperatures should be used to avoid exposing the rider to these hazards in the event that an accident exposes the rider to a live circuit or lamp.
In a wireless system, a power source such as a battery must generally be attached to the helmet. For the helmet assembly, a small battery is beneficial for several reasons. First, a large, heavy battery may cause discomfort for the rider. Additionally, large batteries are generally more expensive than smaller batteries. To complement a smaller battery, the power draw of the receiver components should be minimized to lengthen battery life and reduce the need for battery recharge or replacement. On the other hand, for a helmet lighting system to be effective, a minimum lamp illumination intensity must be provided to allow nearby motorists to see the lamp signal. Consequently, there is a need to produce a high intensity helmet lighting system that is energy efficient.
Heretofore, suggestions have been made to achieve energy efficiency in a helmet light system. For example, U.S. Pat. No. 5,353,008 which issued to Eikenberry et al. for an invention entitled xe2x80x9cHeadgear with Safety Lightxe2x80x9d discloses a motorcycle helmet with a brake light that includes a duty cycled receiver circuit for receiving a radio-frequency signal from a transmitter located on the motorcycle. Rather than using a duty cycled receiver circuit, the present invention uses a duty cycled power circuit to energize the brake lamp. This advancement recognizes that modern receiver circuits use relatively little power, and that most of the power that is dissipated in a helmet lighting system is used to energize the lamps. Further, the present invention contemplates that a helmet mounted running lamp may be operable whenever the motorcycle is in use. This continuous lamp usage mandates that energy efficiency be achieved in the lamp circuit.
In light of the above, it is an object of the present invention to provide an energy efficient lighting system for a vehicle helmet. It is another object of the present invention to provide a wireless system capable of displaying brake lights, running lights, turn indicators, hazard lights, and emergency lights for police motorcycles, on a single vehicle helmet. It is yet another object of the present invention to provide a helmet lighting system having a transmitter capable of broadcasting a unique code set, thereby preventing interference between motorcycles when two or more system equipped motorcycles are in close proximity. It is yet another object of the present invention to provide a helmet lighting system having a transmitter capable of broadcasting more than one code set, thereby allowing several helmet receivers to be used independently with one transmitter. Yet another object of the present invention is to provide a helmet lighting system that is safe, easy to use and comparatively cost effective.
The present invention is directed to a helmet lighting system for a motorcycle helmet that includes a transmitter mounted on a motorcycle for transmitting a radio-frequency signal to a receiver mounted on the motorcycle helmet. The transmitter further includes a transmitter microprocessor that is mounted on the motorcycle and connected to the lighting circuits of the motorcycle. Specifically, the brake light circuit, the running light circuit, the turn signal circuits and the hazard circuit can all be monitored by the transmitter microprocessor. When the transmitter microprocessor receives a voltage from one of the motorcycle lighting circuits indicating that the lighting circuit is energized, the transmitter microprocessor generates a function-specific code and sends that code to a modulator. The modulator receives the code from the transmitter microprocessor and modulates the code onto a radio-frequency signal for transmission by an antenna.
The helmet lighting system further includes a receiver mounted on the helmet. The receiver energizes one or more lamps in response to the radio-frequency signal from the transmitter. The lamps are mounted on the exterior surface of the helmet and positioned to face rearward. For the present invention, the receiver includes an antenna, a demodulator and a receiver microprocessor, all attached to the helmet. The antenna receives the radio-frequency signal containing the function-specific code and forwards the signal to the demodulator. Next, the demodulator extracts the function-specific code from the radio-frequency signal and forwards the code to the receiver microprocessor.
To ensure that the radio-frequency signal that is received by the helmet originated from the proper motorcycle transmitter, the receiver microprocessor compares the received code to a stored code. If the received code does not match the stored code, the received code is disregarded by the receiver microprocessor. If the received code matches the stored code, the receiver microprocessor signals a pulse generator to create a function-specific electrical pulse package in a pulse circuit. Lamps, which may consist of a plurality of light emitting diodes (LED""s) are connected to the pulsed circuit. The function-specific pulse package flows through the pulsed circuit and illuminates the lamps to simulate a specific lighting function such as a brake light. For the present invention, the pulse generator can generate a variety of pulse packages that vary in pulse rate, pulse length, and may contain deenergized periods of varying lengths to thereby simulate the various lighting functions including brake lights, running lights, turn indicators and hazard lights. As such, each pulse package has a duty cycle associated with it that is indicative of the power required to produce the lighting function. By varying the features of the pulse package, lighting functions having different lamp illumination intensities and flashing patterns can be created. For example, to simulate a brake light, the function-specific pulse package generated by the pulse generator may consist of pulse periods having relatively high pulse rates and relatively long pulse lengths, with short de-energized periods interposed between the pulse periods. The result is a high intensity light with a visibly noticeable flash that requires less power than a continuous high intensity light. Conversely, to create the low intensity light needed to simulate a running light, the function-specific pulse package generated may consist of pulse periods having relatively low pulse rates and relatively short pulse lengths, with or without de-energized periods interposed between the pulse periods.
A power source such as a battery is provided in the receiver to supply power to the pulse circuit, receiver microprocessor, antenna and demodulator. To conserve energy during non-use, a motion sensor is provided in the receiver to disconnect the power source from the remaining receiver components if the helmet remains motionless for a predetermined time interval. The receiver microprocessor will prevent the motion sensor from disconnecting the power source if any function-specific codes are received from the transmitter during a predetermined time interval. Once the power source is disconnected, any motion detected by the motion sensor will cause the power source to be reconnected to the remaining receiver components.
For purposes of the present invention, it is desired that each transmitter broadcast a set of codes that are unique to the transmitter to prevent interference between motorcycles when two or more system equipped motorcycles are in close proximity. Further, it is desired that a single transmitter have the capability to broadcast more than one code set to allow several helmet receivers to be used independently with one transmitter. To satisfy these objectives, the helmet lighting system provides a teach and learn protocol for establishing a wireless communication link between a transmitter and a receiver. Specifically, a transmitter can be toggled between a teach mode and an operational mode by the manual manipulation of a mode switch connected to the transmitter microprocessor. To accommodate several helmet receivers, each transmitter can include primary and secondary teach modes and primary and secondary operational modes. Similarly, each receiver can be toggled between a learn mode and an operational mode by the manual manipulation of a mode switch connected to the receiver microprocessor. In one embodiment of the present invention, a cord extending from the transmitter is used to toggle the receiver into learn mode. When the cord is engaged in a socket on the receiver, the receiver toggles into learn mode and sends a signal through the cord to the transmitter verifying that learn mode has been set.
Upon placing the transmitter in a teach mode, the transmitter microprocessor first establishes a unique code set for the receiver. The established code set consists of a function-specific code for each of the motorcycle lighting circuits, such as the brake, running light, turn signals and hazard circuits, that are to be simulated by the helmet lamps. In one embodiment of the present invention, the transmitter microprocessor randomly selects the codes for the code set from a group of at least 2500 potential codes, thus creating a unique code set. In another embodiment, unique codes for each code set are factory selected, and remain fixed for the life of each transmitter. Once the code set is established, and while the transmitter is still in teach mode, the transmitter modulates the code set onto a radio-frequency signal and broadcasts the signal through the transmitter antenna. When the code set is received by a receiver that is set in learn mode, the receiver will store the code set in memory, overwriting any previously stored codes. When the code set is received by a receiver that is set in operational mode, the receiver will not overwrite the stored codes in response to a transmitted code set. Once the code set has been stored by the receiver, the transmitter can be placed in operational mode by manual manipulation of the mode switches. The receiver can be placed in operational mode by removing the cord, or, if a cord is not used, by toggling a mode switch. As indicated above, a transmitter may be placed in a secondary teach mode for teaching a second code set to a second helmet, such as a passengers helmet. Once both helmet receivers have stored a unique code set, one of the helmets can be selected for operational use by setting the mode switch on the transmitter to the desired operational mode for the selected helmet (primary operational mode or secondary operational mode).